Various tourniquet devices that use a wide variety of clamping and/or pneumatic means to apply pressure to various limbs on the body have been attempted. However, prior attempts at cessation of hemorrhage from the major blood vessels of the body at or below the inguinal area have not been no completely successful, especially if attempted on gross battle-field wounds such as leg amputations due to anti-personnel mines or high velocity bullet percussion wounds to the lower extremities. Quite often, such wounds do not provide a satisfactory compressible site to stop arterial hemorrhages and require occlusion of the abdominal descending aorta to cut-off the blood supply to the wound in order to protect the patient's life.
However, compressing the abdominal descending aorta is a difficult exercise. One of the major obstacles to providing an effective portable abdominal aortic tourniquet is in providing a focused compression force over the targeted area on the abdomen to achieve aorta occlusion. Typically, most tourniquets apply a constricting force around the circumference of a limb or over a broad area to reduce total blood flow through the limb. Such a broad application of force is ineffective to reduce or occlude blood flow through the descending aorta proximal to the bifurcation in the abdomen due to the deep location of the aorta in the body. A strong focused pressure is required to reach the descending aorta and reduce blood flow. Prior inventions fail to show or disclose a technique for focusing a compression force in the abdomen to operate as an abdominal aortic tourniquet.
For example, U.S. Patent Application Publication No. 2007/0191881 A1 (Amisar et al.) shows a tourniquet that includes a pressure source and a selector lever attached to a cam to facilitate manual selection of a designated pressure. This tourniquet is designed to apply pressure around a limb. There is no teaching in the patent that this device would be effectively usable as an abdominal aortic tourniquet. Further, the air bladder is not a directed air bladder that would focus the compression force, but is rounded to wrap around the limb and spread the pressure force over a broad area. Such a broad application of constricting force is unusable if intended to reduce or occlude circulation through the descending aorta for a non-compressible arterial hemorrhage in the abdominal region.
U.S. Pat. No. 5,234,459 (Lee) shows an inflatable balloon for use in a tourniquet, and discloses a manual pump for inflating the balloon. U.S. Pat. No. 6,884,254 (Brooks) shows a tourniquet system that includes a lever assisted clamp means for tightening the strap around a limb. This patent is representative of a large section of the prior art that uses mechanical means, as opposed to pneumatic means, to provide a constricting force around a limb, but which fail to provide the directed compression force required to restrict blood flow through the descending aorta.
More recent devices have gotten closer to providing reliable occlusion, but require a relatively high degree of experience and skill to apply the device to a patient to achieve satisfactory occlusion to the descending aorta. For example, U.S. Pat. No. 9,149,280 (Croushorn) uses a standard quick connect buckle to connect a strap encircling the intended patient and a windlass to tighten the tourniquet prior to inflating an occluding bladder. While effective, the arrangement nevertheless requires relatively precise placement of the bladder over the intended compression area and re-adjustment of the device during inflation to obtain the intended occlusion results. Moreover, the narrow end of the directed air bladder must be guided during inflation to ensure the successful application of pressure to the targeted abdominal area. In a field environment where many types of emergency response personal with varying types of experience and skill are present, successful administration of the device may require successive attempts to achieve aortic occlusion, or if not properly adjusted may only obtain partial aortic occlusion.
The apparatus disclosed in U.S. Pat. Nos. 9,782,182 and 9,351,737 issued to Carmichael also utilizes a combination of a bladder and windlass design to attempt to focus the tip of the bladder into the abdomen to occlude the descending aorta (similarly to Croushorn). However, Carmichael includes a monolithically arranged bladder shape requiring a pocket into which a sealed bladder is inserted, and which provides a protective cover over the sealed bladder once assembled. The design also includes a pair of “wings” depending laterally from the pocket portion to purportedly strengthen and support the bladder against a retaining belt. In one embodiment, Carmichael utilizes a pair of retaining belts affixed to these wings. The Carmichael monolithic bladder arrangement potentially simplifies manufacturing of the bladder by allowing the entire sealed bladder, cover, and wing portions to be made from a single piece of material and welded using a radio frequency welding source. Nevertheless, the Carmichael design, as with Croushorn, does not self-stabilize the tourniquet against a patient to ensure a perfected penetration of the abdomen to cause reliable aortic occlusion.
Therefore, what is needed is a self-stabilizing, portable abdominal aortic tourniquet that can be rapidly applied under field conditions without extensive training or skill by emergency response personnel.